For all kinds of existing energy sources in the earth, solar energy is the most widespread, the richest and the most uniformly distributed energy source. Solar energy can be used very easily. It is available every day, everywhere and for everybody. For all kinds of human energy consuming activities, food and beverage cooking is the most important activity and has the longest history. Therefore, it is very interesting and valuable topic to use solar energy for food cooking.
The solar radiation intensity is varied at different regions of earth, and also varied at different time during the day and different seasons. The solar radiation intensity also is affected by the weather, so that to develop an economic effective solar cooking appliance is always a challenge and required continuous efforts.
To overcome the above mentioned difficulties, some of the solar cooking appliances employ a large sunlight receiving area. But the heat insulation for the received heat presents another challenge. Some solar cooking appliances follow and focus the sunlight using an expensive automation system, which requires additional power to operate. Some solar cooking appliances also use the heat storage materials, but the materials may be expensive and not easy to get. There are two prior arts disclose appliances having solar cooking function. They are Muller, Dr. HEINZ-JOACHIM, “Solar Steam Cooker”, 46th ANZSES (Australia and New Zealand Solar Energy Society) conference [online], ISES-AP 2008 and Jiang-Tian Zhao (Zhao, et al.) CN 201206904 Y, “Solar Water Heater”, March 2009 (11 Mar. 2009). Both applied the evacuated tube solar heat collector to heat water or to provide steam for food cooking. So the cooking temperature is limited at the water boiling temperature.
At present time, electric power demand management becomes more popular. One of the management methods is to store the electric heat at the lower power demand period for using at the high demand period. The solar cooking range/stove of this disclosure has very good heat insulation and can be a large heat energy storage device. So the solar heat range/stove can also be an electric heat storage container for electric power demand management purpose.
Therefore, it is an important topic for the industry to further develop and improve applications of the solar cooking technology to develop a set of economic and practicable solar cooking appliances.